An electric vehicle (EV) charging system may be defined as a system for charging a battery of an EV by using power of a commercial power grid or an energy storage system. Such an EV charging system may have various forms according to types of EVs. For example, an EV charging system may be a conductive type system using a charging cable or a non-contact wireless power transfer (WPT) type system (also referred to as an ‘inductive type’).
In the case of the inductive type charging using a WPT system, when a high-voltage battery mounted on the EV is to be charged, the EV maybe positioned to a ground assembly (GA) located in a charging station or a charging spot capable of EV charging.
When charging the EV, a vehicle assembly (VA) (i.e., a reception pad in the VA) mounted on the EV makes an inductive resonance coupling with a transmission pad of the GA located in the charging station or the charging spot, and charges the battery in the EV using power transferred from the GA through the inductive resonance coupling.
Moreover, the reception pad (i.e., a secondary pad) installed in the EV is limited in size, weight and arrangement position when it is mounted on the EV. Also, considering the efficiency of WPT, it may be installed usually in a position as close as possible to the transmission pad (i.e. a primary pad), so that the degree of freedom in installation of other parts of the EV is limited. Therefore, in the design of the EV, the secondary pad may have a bad influence on the degree of freedom such as placement of parts.